Protective device for remote-control systems



March 18,` 1952 .1. F. GRIFFIN PROTECTIVE DEVICE FOR REMOTE-CONTROL SYSTEMS Filed May l0, 1947 /NVE/V TOR JOSEPH F'. G/Q/FF//V all] -ation is to be carried out.

Patented Mar. 18, 1952 UNITED ,srAr-Es PATENT OFFICE V"The present inventionrelates to pneumatic controlQsystems forregulating the operation for variousmechanisins `.from a remote point and particularly to an improved system for pneumatcally operating andcontrolling t-heposition ofthestam throttle valve of a locomotive from nueces In. pneumatic control systems of the typecon "ftmplated herein a regulable :pressure-control tans'iiitteratthe'control Station determines the variablepressure of air conducted `from a supply Vsource through alpipeto a' receiver or translator for 'governing the air pressure Asupplied to a pneumaticmotorvat the -po'int where the opermotive, `a lever "i'nlthe'locomotive 'cab is 'adjustableto regulate tlepressure of air conveyed 'through a pipe extending along thesidesofthe Alocomotive to Yrriechanism that actuatesthe locomotivethrott1e"valvewhich is located forwardly of the 'cab' on the locomotive' as; for example,

in the 'smoke box in the 'case ofv multiple throttlesiY The pressure conveyed through the control pipey is'received by a translator and governs the pressure supplied to and extent of operation of a pneumatic motor which is rmechanicallyicoupled -to the operatingvshaftof thef'locomotive throttle so as to movelit from open to closed position and adjust it iii-various positions in between. Inasmuch as the control pressure is conducted through a pipe'running alongthe side "of the locomotive there isv apossibilit'y that if the pipe breaksthe" throttle 'might on release of pressure suddenly close. Although the probability of this controlpipe'breakingis rather4 Vremotejit is the object of the present invention to provide protective devices which will guard against such a possibility.

The invention will be best understood upon consideration of an illustrative embodiment thereof when read in conjunction with the accompanying drawings in which:

Figure 1 is a diagrammatic view illustrating` the application of a pneumatic control system to a locomotive for regulating the throttle valve at the front end thereof by remote control from the locomotive cab; and

Figure 2 is a diagrammatic view on a larger scale of the pneumatic control system with some parts of the protective apparatus embodying the present invention shown in section to illustrate details of its construction.

Referring first to Figure 1 the numeral I designates an air reservoir from which a pipe II lea-ds to a pneumatic pressure-control trans- As appliedto a loco- 2 Claims. minier- 153) f2 mitter vA mounted inthe locomotive cab. iManipulation of the control lever I2 of thetransfmitter A regulates the airpressure which is conducted through-'piping 63A, I3B, to a receiver or translator Bmounted near the front end of the'locomotive. `Acting in accordance withthe control pressure the -receiver B .governs Vthe amount'fand hence pressure of -air which the .pneumatic vpiston motor C' may receive fromthe reservoirlcthrough ya. pipe `le lfor the purpose of lactuating the shaft I5 of the locomotive throttle. lThe motor C is mechanically vconnected-tothe throttle shaft i5 by a lever I5 interposed between the shaft of the locomotive throttle-and the piston Il of the pneumatic motor 1C. Thus-as the lever I2of-the transmitter vA is moved to increase or decrease Ythe pressure conveyed through the piping i-BA, I3B to the receiver B, the latter governs-thepressure that may be received by the throttle actuating motor C-from the reservoir I The receiver Bl has a follow-up lever 20 connected with the piston I of motor C for cooperation with theadjustable l piston-like stop 2| ofthe receiver B to` govern the` positionof valves within the receiver for the purpose of regulating ,the pressure of air sup- .plied to the motor C to operatefit for lactuating thethrottle in prompt and accurate compliance with.` manipulation `of `the' cab lever I 2.

VA. special control line 25 `isalsoprovided so 'that' when desired thelocomotive throttle may be vclosed, quickly, that is at a rate faster than effected through gradual movementsof lever I2.

inasmuch-as mechanisms of this type aregenerally known none of the detailed construction lofthe transmitter A or the receiver B are described" herein since it is deemedthat a yf reneral description of the systemwill suice'for' the purposes of the present speciiication.

In accordance with the invention instead of employing a single pipe through which to conduct the controlnpressure determined by the operating lever I2 in order to operate the throttle actuating motor C, a pair of pipes H3A and I3B convey the control pressure from the transmitter A to receiver B. At each end of the pressure line adjacent the transmitter A and the receiver B, or preferably within the bodies thereof, valve mechanisms 32 and 32A are provided which act normally so that the same control pressure as regulated by lever I2 is conducted through both pipes between the transmitter A and the receiver B while also assuring that the control pressure is 3 the reservoir l through the pipe H as modified by the adjustment of the control lever I2 is conveyed through a channel or nipple 30 into a chamber 33 in the body of valve 32. From this chamber passages 34 and 35 lead to the pipe I3A and I3B, respectively. The ports 36, 31 admittingA the air from the chamber 33 to these passages are located directly opposite each other with a flexible diaphragm 38 interposed between them and adapted to seat against either of the ports36, 31 and shut oi the communication between the chamber 33 and the relatedlpassage 34, 35. Where, as is shown in the drawings, the diaphragm 38 is mounted and held in-placebetween two halves of the valve body-32 one'or more orifices 4U are formed through the diaphragm 38 so that equal pressuremay bernaintained on both sides thereof and so that both passages 34 and 35 are in communication with the chamber 33, At the-receiving end of the line a similar valve 32A is mounted and thechamrber 33A thereof is connected by asingle-nipple lever I2 is followed by corresponding opening` and/or closing movement of the locomotive throttle as varied pressures are conveyed through both the pipes I3A, 13B and interpreted bythe Although a specific form of protective valve has been described in detail herein, it will be understood that the protective principles illustrates by this structure may equally well be embodied in differential pressure valves of other construction but operating to achieve the same ythereto or receiving it therefrom; a flexible, pressure deformable diaphragm extending through said slot-shaped port between opposite sides thereof and projecting from said dividing wall across `the other of said chambers so as to divide it into two separate sections; a pair of conduits each connected to one section of said other chamber at opposite sides of said diaphragm; and means securing said diaphragm to said body at opposite sides of said dividing wall so that when the diaphragm is subjected to unequal pressures on its opposite sides it contacts one or the other receiver B to govern the movements of the throtl tleractuating motor C. Under such conditions. whatever may be the setting of the control lever,

l2 to govern the throttle, equal'pressures exist in the-pipes |3A and 13B and therefore on oppo-V site sides of the diaphragms 38 and38A-within protective valves 32, 32A with the result that the portsrelated to the broken pipe to close off the leaking line. For example, if the pipe |3A breaks the pressure on the under side of the dia'- phragms 38 in valve 32 becomes greater than on the upper side, the diaphragmA moves against theY seat around port 36 thereby cutting off communication between the chamber 33 and passage 34. Atthe same time the diaphragm in valve 32A at the opposite end of the pressure line also closes offthe passage 34A in this valve so that the pres-- sure: which is retained in the pipe |3B is not dis-A sipated via the chamber 33A back through the pointat which the pipe I3A broke.

passage 34A and pipe 13A to bleed off at they side of said slot-shaped port to cut oi communication between said rst chamber and that section of said other chamber in which the lower pressure exists, whereby when leakage occurs from one or the other of said pair of conduits communication between the related section of said second chamber and said first chamber is cut oft.

2. `A protective valve as defined in claim 1 in which ports for the conduits leading from said second chamber are formed in closely adjacent relation in its outer wall opposite said dividing wall and the ilexible diaphragm is attached at one end in a position between said ports-so as to be subjected on opposite sides to the pressures existing in the respective pipes.

- JOSEPH F. GRIFFIN.

REFERENCES CITED The following references are of record in the le of this patent:

y UNITED STATES PATENTS Number 

